Analysis of the gut-specific microbiome from critically endangered hawksbill sea turtles (Eretmochelys imbricata) using a culture-dependent approach

Hongwei Li^1*Yuan Chen¹Zhong-rong XIA²Yunyong Lin³Ruijun Xu³

• ¹Huizhou University, Huizhou, China
• ²huidong sea turtle national natural reserve bureau, guangdong, China
• ³Key Laboratory of Marine Biological Genetic Resources, Xiamen, China

The critically endangered hawksbill turtle (Eretmochelys imbricata) plays a vital role in maintaining the health and resilience of coral reef ecosystems. The gut microbiota of hawksbill turtles is closely linked to host nutrition and overall health. Therefore, understanding the diversity of these microbial communities is crucial for the effective conservation of hawksbill turtles. However, previous findings remain insufficient for a comprehensive understanding of gut microbiota diversity. Laboratory-based cultivation of gut bacteria offers a promising avenue for elucidating their roles in hawksbill turtles. Therefore, we aimed to characterize the bacterial taxa isolated from the fecal samples of hawksbills. Using two distinct bacterial media under aerobic and anaerobic conditions, 161 bacterial strains were successfully isolated and classified into three phyla: Pseudomonadota (formerly Proteobacteria), Actinomycetota, and Bacillota (formerly Firmicutes). The most frequently identified species were Psychrobacter celer, Shewanella algae, Sulfitobacter pontiacus, Vibrio mytili, Enterococcus hirae, and Psychrobacter maritimus. Furthermore, 10 isolates were determined to represent six novel bacterial species potentially. Our study expands current knowledge on the microbial diversity associated with hawksbill turtles. It illustrates how fast and simple culture-dependent approaches can be applied to characterize the microbiota of endangered species.